(+/-)-CP-96,345, AN NK1 RECEPTOR ANTAGONIST, HAS LOCAL ANESTHETIC-LIKE EFFECTS IN A MAMMALIAN SCIATIC-NERVE PREPARATION

The effect of the non-peptide NK, receptor antagonist (+/-)-CP-96,345 was investigated on the compound action potential (cAP) recorded in the isolated guinea-pig nerve, and compared to the effects of the local anaesthetic lidocaine and the L-type Ca2+ channel antagonist diltiazem. (+/-)-CP-96,345, as well as lidocaine and diltiazem, produced a concentration dependent reduction of the cAP amplitude. All three drugs showed frequency dependent block. The block of the cAP by lidocaine was fully reversible at all concentrations tested, while the block by(+/-)-CP-96,345 and diltiazem were only partly reversible at higher concentrations. The present findings indicate that (+/-)-CP-96,345 exerts a local anaesthetic-like effect on nerve conduction.